California will overhaul the way most utility customers are billed for home electricity and lift current caps on the amount of renewable energy and rooftop solar installations, under legislation that cleared its last major hurdle on Monday.

Approval of Assembly Bill 327 by the state Senate opens the way for the California Public Utilities Commission to rewrite landmark consumer protections and energy conservation measures enacted during the state’s 2000-01 energy crisis.

Gov. Jerry Brown is expected to sign the bill after the State Assembly reviews an updated version. The Senate vote was 33-5.

The state's three investor-owned electric utilities, including San Diego Gas & Electric, argued that current rules have thrust rising utility costs disproportionally upon large consumers of home electricity, gradually undermining effective funding of the power distribution grid. Amid months of bargaining among industry and consumer groups, negotiations were broadened to address a simmering standoff over incentives and sunset provisions for rooftop solar that loomed over the rapid growth of the industry.

The bill advancing Monday would extend until July 2017 the current equation for so-called net metering, which allows utility customers to credit energy production against consumption with some additional credits. By mid-2017, utility regulators are required to establish new terms and conditions for rooftop solar -- dubbed "Net Metering 2.0" by industry watchers.

"It lays the groundwork for a completely unlimited solar market," said Bernadette Del Chiaro, executive director of the California Solar Energy Industries Association, one of the last holdouts in negotiations.

The utility commission has until the end of March to come up with a transition plan for current solar customers, taking into consideration the pay-off time for solar equipment investments.

Overall limits on the state's renewable energy mix, capped at 33 percent, would be lifted.

When it comes to electricity charges, new consumer protections include an average discount of 30 percent to 35 percent for low-income households now qualifying for the California Alternative Rates for Energy program -- who typically earning under 200 percent of federal poverty guidelines. That relief that could be weighted further by regulators toward the more needy.

Fixed charges for utility services would be limited to $10 per month, and $5 per month for low-income customers, indexed for future inflation. Environmental and some consumer groups are concerned that adding fixed rates will discourage conservation incentives.

Matt Freedman, attorney for The Utility Reform Network, said his group and others will continue to lobby against fixed charges.

"There is a cap on the maximum amount of fixed charge that the PUC could ever approve" under the pending legislation, he said. "The PUC does not need to approve any fixed charge at all."

The bill sets out guidelines for a transition to "time of use" charges based on the time of day when electricity is consumed.

Those charges, made possible by the deployment of high-tech "smart" meters, can reward customers for conserving at times when demands and costs are highest, potentially reducing the need for certain power lines and plants. But consumer groups remain wary of impacts on stay-at-home customers or those who can't afford appliances with sophisticated timers and communications capabilities.